Chopper stabilized delta-sigma analog-to-digital converter

ABSTRACT

A chopper stabilized analog-to-digital converter includes an analog modulator (10) and a digital filter (12). The analog modulator (10) is comprised of two integrators (20) and (22). The first integrator (20) is a chopper stabilized integrator which is comprised of a chopper stabilized differential amplifier (32) and a capacitively switched input. The amplifier (32) is operable to receive a chopping frequency FCH that is one-half the sampling frequency FS and synchronized thereto. The amplifier (32) is operable to modulate the noise up to the chopping frequency FCH, which frequency is in the rejection portion of the filter response for the digital filter (12), thus rejecting 1/f noise.



